I. Field of the Invention
The present invention relates generally to network management systems, and more specifically is directed toward management of network resources using distributed intelligence and state management.
II. Related Art
Telecommunication service providers provide a wide range of services to their customers. These services range from the transport of a standard 64 kbit/s voice channel (i.e., DS0channel) or subrate thereof to the transport of higher rate digital data services (e.g., video). Both voice channels and digital data services are transported over the network via a hierarchy of digital signal transport levels. For example, in a conventional digital signal hierarchy 24 DS0 channels are mapped into a DS1 channel. In turn, 28 DS1 channels are mapped into a DS3 channel. The number of customers served and the complexity of services offered by telecommunication service providers is always increasing.
The wide range of services, signals and channels require a complex network of telecommunications equipment. Management of the complex telecommunications network is necessary in order to maintain optimum levels of service to the customer as well as efficiency in the maintenance and usage of the equipment itself. As networks grow increasingly complex, both in the size of the network and the range of services provided by the network, network management becomes increasingly important. Telecommunications service providers provide for management of the network by implementing network management systems designed to manage, provide for growth and ensure optimum performance of the network.
Network management systems include at least two layers. The first layer is the network management layer. The network management layer includes a network manager that monitors and controls the configuration of the network. The network manager is usually a server and software that maintains a logical representation of the state and condition of the network. The network manager provides an interface to the network for users and applications wishing to manage the network.
The second layer of the network is the network element layer. The network element layer includes all of network elements. Examples of network elements are the mobile switching center (MSC), call detail adjunct (CDA), home location registry (HLR), channel service unit (CSU), customized dial plan (CDP), CDMA interconnect subsystem (CIS), etc. The network elements provide the functionality and services of the entire network, independent of the network manager.
The network management system implements a set of procedures, software, equipment and operations designed to keep the network operating near maximum efficiency. The goals of network management include configuration management, fault location and repair management, security management, and performance management.
Configuration management deals with installing, initializing, loading, modifying and tracking configuration parameters, network elements and their associated software. The network manager accomplishes configuration management by downloading configuration parameters and software to the network elements. The network manager also tracks the configuration of the network by retrieving data indicating the configuration of the network elements and their associated software.
Fault location and repair management predicts and diagnoses problems with the network and provides a methodology for replacing or rerouting the network around the affected network elements. The network manager accomplishes fault location and repair management by retrieving fault information from the network elements in the network element layer. For example, the network manager may retrieve the number of severely errored seconds (SES) or the frame error rate (FER) from a network element in order to locate faults and diagnose problems with the network. If, upon retrieval of fault information from the network element layer, the network manager determines that particular network elements are experiencing degraded performance or are inoperative, the network manager may reroute the network around the affected elements. The network manager accomplishes the rerouting function by downloading additional configuration information to the network elements in order to reconfigure the network.
Security management allows the network manager to restrict access to various resources in the network, thereby giving customers different levels of access to different network resources. The network manager accomplishes security management by retrieving the current security information from the network elements and analyzing the retrieved information. If the access to resources in the network is to be changed, the network manager accomplishes the change by downloading additional or changed security information to the network elements, thereby changing the levels of access the users have to the network resources.
Performance management provides statistical information about the network's operation allowing the network manager to manage the resources of the network to ensure optimum performance. The network manager monitors the usage and traffic levels of the network element to ensure that the traffic on the network is properly distributed. Proper distribution of traffic among the network elements helps to ensure that the network does not experience performance degradation because a few network elements are carrying most of the communications load, while other network elements are carrying too little. The network manager accomplishes performance management by retrieving information pertaining to the traffic loading of the particular network elements. If the network manager determines that the performance of the network would be improved by redistributing the network traffic from one set of network elements to another, the network manager downloads additional configuration information to the network elements, thereby reconfiguring them.
Network management, therefore, is accomplished by communication between the network manager and the network elements. A telecommunications network may contain tens of thousands of network elements. A network manager, therefore, may be interacting with thousands of elements at a time. It is not practical for the network manager to spend time establishing synchronous connections with each of the network elements that it wishes to communicate with, if it must establish thousands of such connections to manage the network.
A more practical solution to the problem of communication between the network manager and the network elements is asynchronous communication. In asynchronous communication, messages containing requests, commands and data are transmitted between the network manager and network elements over the network. In such a system, messages transmitted from a network element before others may arrive at the network manager after the later transmitted message. Context information about the network management system, therefore, may not be assumed or inferred since a received message may not reflect the current state of the system.
Asynchronous communications pose additional management problems. Often, when the network manager sends a message to a network element, it must wait for a response. The management functions of the network manager often require information to be retrieved from multiple subsystems. If the network includes thousands of network elements, this serial process of messaging and response becomes too slow for practical network management. Current asynchronous packet network management systems are unable to handle concurrent outstanding messages sent to the subsystems.
Furthermore, messages between the network elements and network manager perform differing functions. Some messages communicate information, or data, between the network manager and the network elements, or between the network elements themselves. Other messages cause actions to be performed. Current messaging systems for network management implement different systems to accommodate the different types of network management messages.
Additionally, a network may contain multiple hierarchical layers. In order for a network manager to communicate with the multiple layers, current messaging systems require the implementation of multiple messaging protocols. Multiple messaging protocols allow the network manager to communicate with network elements existing at multiple levels within the network management system hierarchy. Multiple network management protocols make the communication between the network manager and the network elements, as well as between the network elements themselves, complex and error prone.
What is needed, therefore, is a network management messaging system which is capable of sending and receiving multiple concurrent messages to the network element layer from the network management layer. Such a system would greatly increase the speed with which the network can be managed. The network management messaging system should provide a universal message handling method that handles both information and action messages. Such a system should also provide for interacting with network elements at differing levels within the network management hierarchy, and between the network elements themselves.